How can i find Set of Unique Elements In 2d Vector in most EFFICIENT WAY??

Vector Declaration :

```
vector <int> par[100000];
```

Example :

Input :

1,2,3,4

1,4,3,2

1,2,3,4

5,4,2,9

8,6,5,4

1,2,3,4

Output :

1,2,3,4

1,4,3,2

5,4,2,9

8,6,5,4

How can i find Set of Unique Elements In 2d Vector in most EFFICIENT WAY??

Vector Declaration :

```
vector <int> par[100000];
```

Example :

Input :

1,2,3,4

1,4,3,2

1,2,3,4

5,4,2,9

8,6,5,4

1,2,3,4

Output :

1,2,3,4

1,4,3,2

5,4,2,9

8,6,5,4

Do you want to perform some operations on the resultant 2D matrix? How about inserting them in a set of vectors.

I guess you want a more efficient way compared to NlogN.(N is the unique number of elements in set). Still thinking an efficient way.

1 Like

You can make trie type structure or you can also use unordered map…

For trie type structure, at each level you would store a column in sorted manner and insert and find element accordingly… This link may help.

```
1 5 8
2 4 4 6
3 3 2 5
4 2 9 4
```

This is how your trie will look like… Hope this will help…

2 Likes

Thanks!!!

Thanks!!

Learned something new!!